Each fill and ellipse function describe a new shape. I’ve given “fill” 4 parameters: red, green, and blue between 0 and 255. Fourth is opacity between 0 and 255. These settings will apply to the circle described next (and any until the next “fill”). I’ve given “ellipse” 4 parameters: x and y coordinates, then width and height.

Forwardslash is a blog about creative technology, programming, the Internet, and digital aesthetics. It's a developer's notebook meets general-interest blog on technology's overlap with other topics. It's written by Justin Allen, a guy who works on websites for a living and has been writing stories for even longer than he's been writing HTML.